Hey there, pdog!
If your order was placed today, that shipping date sounds about right according to this: Shipping dates for new devices | T-Mobile . As far as inventory in the store, it'll vary by location. I recommend reaching out to the store that you plan on going to in order to see what devices they plan on carrying.
I ordered on the day of pre order and I was told the watch would ship on the day of launch. Now my order status is 10/23 - 11/6. Just spoke with rep and they said there is a system glitch and once it is resolved they will know how much inventory they have available to ship. Seems odd to me. After a online chat with a rep, I can place a new order withe them or go to the store and receive it sooner than my pre order.